#include <stdio.h>
#include <time.h>

int f1() {
    int i;
    int j;
    int tmp;
    int loopNum = 10000;
    for (i = 0; i < loopNum; i++) {
        for (j = 0; j < loopNum; j++) {
            tmp = i * j;
        }
    }
    return tmp;
}

int main(int argc, char const *argv[])
{
    const int N = 1e2;
    int i = 0;
    clock_t start, end;
    start = clock();
    for (; i < N; i++) {
        f1();
    }
    end = clock();
    printf("time: %f s\n", ((double)(end - start)) / CLOCKS_PER_SEC / N);
    return 0;
}
